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Ecoregion

Ecoregion

An ecoregion is "a relatively large area of land or water that contains a geographically distinct assemblage of natural communities." This description is part of a definition, by World Wildlife Fund that is widely accepted and used. However, the use of the term "relatively large" is interpreted differently in different locales. Another way of looking at an ecoregion is a "recurring pattern of ecosystems associated with characteristic combinations of soil and landform that characterise that region" (Brunckhorst, 2000). Others have defined ecoregions as areas of ecological potential based on combinations of biophysical parameters such as climate and topography. Biodiversity is also an important aspect of the study of ecoregions. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tend to be distinct from that of other ecoregions. World Wilfdlife Fund's full definition of an ecoregion is the following: :A large area of land or water that contains a geographically distinct assemblage of natural communities that ::(a) share a large majority of their species and ecological dynamics; ::(b) share similar environmental conditions, and; ::(c) interact ecologically in ways that are critical for their long-term persistence. :::--[http://www.worldwildlife.org/science/ecoregions.cfm World Wildlife Fund - Ecoregions] World Wildlife Fund ecologists currently divide the land surface of the Earth into 8 major ecozones containing 867 smaller terrestrial ecoregions (see list). Many consider this classification to be quite decisive, and some propose these as stable borders for bioregional democracy initiatives. The ecozones are very well-defined, following major continental boundaries, while the ecoregions are subject to more change and controversy. The use of the term ecoregion is an outgrowth of a surge of interest in ecosystems and their functioning. In particular, there is awareness of issues relating to spatial scale in the study and management of landscapes. It is widely recognized that interlinked ecosystems combine to form a whole that is "greater than the sum of its parts." There are many attempts to respond to ecosystems in an integrated way to achieve "multi-functional" landscapes and various interest groups from agricultural researchers to conservationists are using the ecoregion as a unit of analysis.
See also

- Biome
- Ecozone
- Ecotope
- Fresh water ecoregion
- Global 200
- Habitat
- Marine ecoregion
- Terrestrial ecoregion
Sources

- Brunckhorst, D. 2000. Bioregional planning: resource management beyond the new millennium. Harwood Academic Publishers: Sydney, Australia.
External links

- [http://www.worldwildlife.org/ecoregions/ World Wildlife Fund: ecoregions ]
- [http://www.sierraclub.org/ecoregions/ Sierra club: ecoregions]
- [http://www.planetdrum.org Activist network cultivating Ecoregions/Bioregions]
- [http://sis.agr.gc.ca/cansis/nsdb/ecostrat/intro.html A National Ecological Framework for Canada]
- [http://www.epa.gov/wed/pages/ecoregions/na_eco.htm#Level%20I Ecoregions of North America] Category:Ecology Category:Ecoregions Category:Biogeography

World Wildlife Fund
:Note: After losing a court case in 2002 on the use of the initials WWF, the organization previously known as the World Wrestling Federation has rebranded itself as World Wrestling Entertainment, or WWE. rightWWF, the global conservation organization, was originally known as World Wildlife Fund. In 1986, it changed its name to World Wide Fund For Nature (except in the US and Canada) to better represent the spread of its work. It was founded on September 11, 1961 by, among others, the biologist Sir Julian Huxley, Prince Bernhard of the Netherlands, Max Nicholson and the naturalist and painter Sir Peter Scott who designed the original black and white panda logo. It is one of the world's largest environmental organizations, with a network of offices in nearly 60 countries and a secretariat in Gland, Switzerland. Probably the most famous name associated with WWF is HRH The Duke of Edinburgh. The Duke was the first President of WWF-UK from its foundation in 1961 to 1982, International President of WWF (1981-1996), and is now President Emeritus. WWF is dedicated to stopping the degradation of the planet's natural environment and building a future in which humans live in harmony with nature, by:
- conserving the world's biological diversity
- ensuring that the use of renewable natural resources is sustainable
- promoting the reduction of pollution and wasteful consumption. WWF promotes a factual, science-based approach to conservation, which focuses on six priority issues of global concern: forests, oceans and coasts, fresh water, endangered species, and the insidious threats of toxic chemicals and climate change. For each of these issues, WWF has developed measurable targets and runs more than 1,200 field projects around the world in any year.
Presidents

- 1962-1976: HRH Prince Bernhard of the Netherlands
- 1976-1981: John H Loudon
- 1981-1996: HRH The Duke of Edinburgh
- 1996-1999: Syed Babar Ali
- 2000-2000: Ruud Lubbers
- 2000-2001: The Hon. Mrs Sara Morrison
- 2001-present: HE Chief Emeka Anyaoku
International directors
;WWF Services
- Dr Claude Martin - Director General
- Paul Steele - Chief Operating Officer
- Dorothy Bray - Human Resources Development
- Thomas Schultz-Jagow - Communications
- Dr Timothy Geer- Government & Aid Agency Coordination
- Mario Fetz - Fundraising & Marketing
- Chiew Chong - Finance & Administration ;International Conservation Programme
- Dr Chris Hails - Programme Director
- Dr Sheila O'Connor - Programme Audits ;Regional Programmes
- Dr Yaa Ntiamoa-Baidu - Africa/Madagascar
- Dr Isabelle Louis - Asia/Pacific
- Dr Magnus Sylvén - Europe/Middle East
- Dr Georg Schwede - Eastern Europe/Central Asia
- Dr Guillermo Castilleja - Latin America/Caribbean ;Policy
- Gordon Shepherd - International Policy ;Global Issues
- Jennifer Morgan - Climate Change Programme
- Dr Chris Elliott - Forests for Life Programme
- Jamie Pittock - Freshwater Programme
- Dr Simon Cripps - Oceans & Coasts Programme
- Dr Sue Lieberman - Species Programme
- Clif Curtis - Toxics Programme ;Legal Advisor
- Michael R. Rogers, Barrister See also: Global 200 (200 ecoregions defined by WWF as the most critical regions for conservation), ecoregion
External links

- [http://www.wwf.org/ WWF]
- [http://www.wwf.ca/ WWF: Canada]
- [http://www.worldwildlife.org/ WWF: USA]
- [http://www.wwf.org.uk/ WWF: UK]
- [http://www.panda.org/ WWF: International]
- [http://www.warned.net/wwfarticle Warned.net Article - WWF vs WWF] Category:Climate change organizations Category:International environmental organizations ja:世界自然保護基金

Landform

A landform comprises a geomorphological unit. Landforms are categorised by characteristics such as elevation, slope, orientation, stratification, rock exposure, and soil type. Landforms by name include berms, mounds, hills, cliffs, valleys, and so forth. Oceans and continents exemplify highest-order landforms. A number of factors, ranging from plate tectonics to erosion and deposition can generate and affect landforms. Biological factors can also influence landforms -- see for example the role of plants in the development of dune systems and salt marshes, and the work of corals and algae in the formation of coral reefs. coral reefs

List of landforms

- alas
- continent
- limestone pavement
- plain and plateau
- rock formations

Erosion landforms

Landforms produced by erosion and weathering usually occur in coastal or fluvial environments, and many appear above under those headings. Some other erosion landforms that do not fall into the above categories include:
- canyon
- cave
- limestone pavement
- tea table
- Deposition landform -- landforms produced by deposition of load or sediment (usually coastal or fluvial).
- Eolian landform - landforms produced by wind weathering.

External links

- [http://www.deh.gov.au/settlements/industry/minerals/booklets/landform/ Landform Design] Category:Geomorphology ja:地形

Climate

The climate (ancient Greek: κλίμα) is the weather averaged over a long period of time. The Intergovernmental Panel on Climate Change (IPCC) glossary definition is: : Climate in a narrow sense is usually defined as the “average weather”, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.[http://www.grida.no/climate/ipcc_tar/wg1/518.htm]

Climate vs weather

In the most succinct words, weather is the combination of events in the atmosphere and climate is the overall accumulated weather in a certian location. The exact boundaries of what is climate and what is weather are not well defined and depend on the application. For example, in some senses an individual El Niño event could be considered climate; in others, as weather. When the original conception of climate as a long-term average came to be considered, perhaps towards the end of the 19th century, the idea of climate change was not current, and a 30 year average seemed reasonable (but see note 1). Given the current availability of long-term trends in the temperature record, it is harder to give a precise contradiction-free definition of climate: over a 30 year period, averages may shift; over a shorter period, the statistics are less stable.

Climate determinants

In a given geographical region, the climate generally does not vary over time on the scale of a human life span. However, over geological time, climate can vary considerably for a given place on the Earth. For example, Scandinavia has been through a number of ice ages over hundreds of thousands of years (the last one ending about 10,000 years ago). Paleoclimatology is the study of these past climates, their origin, and by extension, the origin of today's climate. Over historic time spans there are a number of static variables that determine climate including: altitude, proportion of land to water, and proximity to oceans and mountains. Other climate determinants are more dynamic: The Thermohaline circulation of the ocean distributes heat energy between the equatorial and polar regions; other ocean currents do the same between land and water on a more regional scale. Degree of vegetation coverage affects solar heat absorption, water retention, and rainfall on a regional level. Alterations in the quantity of atmospheric greenhouse gases determines the amount of solar energy retained by the planet, leading to global warming (or cooling). The variables which determine climate are numerous and the interactions complex but there is general agreement that the broad outlines are understood, at least in so far as the determinates of historical climate change are concerned.

Climate indices

Scientists use climate indices in their attempt to characterize and understand the various climate mechanisms that culminate in our daily weather. Much in the way the Dow Jones Industrial Average, which is based on the stock prices of 30 companies, is used to represent the fluctuations in the stock market as a whole, climate indices are used to represent the essential elements of climate. Climate indices are generally identified or devised with the twin objectives of simplicity and completeness, and each typically represents the status and timing of the climate factor they represent. By their very nature, indices are simple, and combine many details into an generalized, overall description of the atmosphere or ocean which can be used to characterize the factors which impact the global climate system. Because the climate indices are generally determined from measurements made in a localized area, they can have impacts in other areas around the globe, through processes sometimes called teleconnections. References:
- [http://www.arctic.noaa.gov/essay_bond.html Why and how do scientists study climate change in the Arctic? What are the Arctic climate indices?]
- [http://www.arctic.noaa.gov/climate.html Climate index and mode information]

Classifications

In the original sense, climate is a concept used to divide the world into regions sharing similar climatic parameters. Climate regions can be classified on the basis of temperature and precipitation alone. Examples of such climate schemes are the Köppen climate classification or the Thornthwaite climate classification schemes. For more details about specific climates, please see:
- Tropical climate
- Subtropical climate
- Arid climate
- Semiarid climate
- Mediterranean climate
- Temperate climate
- Oceanic climate
- Continental climate
- Alpine climate
- Subarctic climate
- Polar climate
- Climate of Antarctica To understand a climate of a specific place or area, please see the article on that place or area.

Historical climates

- Climate changes of 535-536
- Medieval climate optimum

National climates

- Climate of the Alps
- Climate of India
- Climate of the United Kingdom

External links

- [http://climateapps2.oucs.ox.ac.uk/cpdnboinc/ Climate Prediction Project]
- [http://www.worldclimate.com WorldClimate]
- [http://www.atmosphere.mpg.de/enid/1442 ESPERE Climate Encyclopaedia]
- [http://www.weatherbase.com Weatherbase]
- [http://www.climate-zone.com Global Climate Data]
- [http://www.limaperunet.com/climate/climateall.html The Climate of Peru]
- [http://www.arctic.noaa.gov/climate.html Climate index and mode information]
- [http://www.arctic.noaa.gov/essay_bond.html Why and how do scientists study climate change in the Arctic? What are the Arctic climate indices?]
- [http://www.arctic.noaa.gov/detect/ A near-realtime Arctic Change Indicator Website]
- [http://www.beringclimate.noaa.gov/ A current view of the Bering Sea Ecosystem and Climate]

Notes

# In "Climatology" by W G Kendrew (OUP; 3rd edition 1949; chapter 38; page 359) we find: "A well-known cycle is one with a mean period of about 35 years... which was worked out by Bruckner... the reality of this cycle seems to be well established, though it is of little use for actual forecasting; it is a basis of the choice of 35 years as the period estimated to give true mean values of climate elements." Category:Ecology ko:기후 ja:気候 simple:Climate

Biodiversity

Biodiversity or biological diversity is the diversity of and in living nature. There are a number of definitions and measures of biodiversity.

Etymology

Biodiversity is a neologism and a portmanteau word, from bio and diversity. The term biological diversity was coined by Thomas Lovejoy in 1980, while the word biodiversity itself was coined by the entomologist E. O. Wilson in 1986, in a report for the first American Forum on biological diversity organized by the National Research Council (NRC). The word biodiversity was suggested to him by the staff of NRC, to replace biological diversity, considered to be less effective in terms of communication. Since 1986 the terms and the concept have achieved widespread use among biologists, environmentalists, political leaders, and concerned citizens worldwide. This use has coincided with the expansion of concern over extinction observed in the last decades of the 20th century.

Biodiversity definitions

Biodiversity is the variety of life: the different plants, animals and micro-organisms, their genes and the ecosystems of which they are a part. Biological diversity has no single standard definition. One definition holds that biological diversity is a measure of the relative diversity among organisms present in different ecosystems. Diversity in this definition includes diversity within species and among species, and comparative diversity among ecosystems. Another definition, simpler and clearer, but more challenging, is the totality of genes, species, and ecosystems of a region. An advantage of this definition is that it seems to describe most instances of its use, and one possibly unified view of the traditional three levels at which biodiversity has been identified: extinction]
- genetic diversity - diversity of genes within a species. There is a genetic variability among the populations and the individuals of the same species
- species diversity - diversity among species
- ecosystem diversity - diversity at a higher level of organization, the ecosystem (richness in the different processes to which the genes ultimately contribute) The lattermost definition, which conforms to the traditional five organisation layers in biology, provides additional justification for multilevel approaches. The 1992 United Nations Earth Summit in Rio de Janeiro defined biodiversity as "the variability among living organisms from all sources, including, inter alia, terrestrial, marine, and other aquatic ecosystems, and the ecological complexes of which they are part: this includes diversity within species, between species and of ecosystems". This is, in fact, the closest thing to a single legally accepted definition of biodiversity, since it is the definition adopted by the United Nations Convention on Biological Diversity. The parties to this convention include all the countries on Earth, with the exception of Andorra, Brunei Darussalam, the Holy See, Iraq, Somalia, Timor-Leste, and the United States of America. If the gene is the fundamental unit of natural selection, thus of evolution, some, like E. O. Wilson, say that the real biodiversity is the genetic diversity. However, the species diversity is the easiest one to study. For geneticists, biodiversity is the diversity of genes and organisms. They study processes such as mutations, gene exchanges, and genome dynamics that occur at the DNA level and generate evolution. For biologists, biodiversity is the diversity of populations of organisms and species, but also the way these organisms function. Organisms appear and disappear; sites are colonized by organisms of the same species or by another. Some species develop social organisations to improve their reproduction goals or use neighbor species that live in communities. Depending on their environment, organisms do not invariably use the same strategies of reproduction. For ecologists, biodiversity is also the diversity of durable interactions among species. It not only applies to species, but also to their immediate environment (biotope) and the ecoregions the organisms live in. In each ecosystem, living organisms are part of a whole; they interact with one another, but also with the air, water, and soil that surround them.

Origin of life and biodiversity evolution

ecoregion] See also biodiversity and evolution Biodiversity found on Earth today is the result of 4 billion years of evolution. The original origin of life is not well known to science, though limited evidence suggests that life may already have been well-established only a few 100 million years after the formation of the Earth. Until approximately 600 million years ago, all life consisted of bacteria and similar single-celled organisms. The history of biodiversity during the Phanerozoic (the last 540 million years), starts with rapid growth during the Cambrian explosion—a period during which nearly every phylum of multicellular organisms first appeared. Over the next 400 million years or so, global diversity showed little overall trend, but was marked by periodic, massive losses of diversity classified as mass extinction events. The apparent biodiversity shown in the fossil record suggests that the last few million years include the period of greatest biodiversity in the Earth's history. However, not all scientists support this view, since there is considerable uncertainty as to how strongly the fossil record is biased by the greater availability and preservation of recent geologic sections. Some (e.g. Alroy et al. 2001) argue that corrected for sampling artifacts, modern biodiversity is not much different than biodiversity 300 million years ago. Estimates of the present global macroscopic species diversity vary from 2 million to 100 million species, with a best estimate of somewhere near 10 million. Most biologists agree however that the period since the emergence of humans is part of a new mass extinction, the Holocene extinction event, caused primarily by the impact humans are having on the environment. At present, the number of species estimated to have gone extinct as a result of human action is still far smaller than are observed during the major mass extinctions of the geological past. However, it has been argued that the present rate of extinction is sufficient to create a major mass extinction in less than 100 years. Others dispute this and suggest that the present rate of extinctions could be sustained for many thousands of years before the loss of biodiversity matches the more than 20% losses seen in past global extinction events. New species are regularly discovered (on average about three new species of birds each year) and many, though discovered, are not yet classified (an estimate states that about 40% of freshwater fish from South America are not yet classified). Most of the terrestrial diversity is found in tropical forests.

Benefits of biodiversity

Biodiversity has contributed in many ways to the development of human culture, and, in turn, human communities have played a major role in shaping the diversity of nature at the genetic, species, and ecological levels. There are three main reasons commonly cited in the literature for the benefits of biodiversity.

Ecological role of biodiversity

All species provide some kind of function to an ecosystem. They can capture and store energy, produce organic material, decompose organic material, help to cycle water and nutrients throughout the ecosystem, control erosion or pests, fix atmospheric gases, or help regulate climate. Ecosystems also provide various supports of production (soil fertility, pollinators of plants, predators, decomposition of wastes...) and services such as purification of the air and water, stabilisation and moderation of the climate, decrease of flooding, drought, and other environmental disasters. These functions are important for ecosystem function and human survival. Research suggests that a more diverse ecosystem is better able to withstand environmental stress and consequently is more productive. The loss of a species is thus likely to decrease the ability of the system to maintain itself or to recover from damage or disturbance. Just like a species with high genetic diversity, an ecosystem with high biodiversity may have a greater chance of adapting to environmental change. In other words, the more species comprising an ecosystem, the more stable the ecosystem is likely to be. The mechanisms underlying these effects are complex and hotly contested. In recent years, however, it has become clear that there are real ecological effects of biodiversity. ecological effects of biodiversity

Economic role of biodiversity

For all humans, biodiversity is first a resource for daily life. One important part of biodiversity is 'crop diversity', which is also called agrobiodiversity. Most people see biodiversity as a reservoir of resources to be drawn upon for the manufacture of food, pharmaceutical, and cosmetic products. This concept of biological resources management probably explains most fears of resources disappearance related to the erosion of the biodiversity. However, it is also the origin of new conflicts dealing with rules of division and appropriation of natural resources. Some of the important economic commodities that biodiversity supplies to humankind are:
- food : crops, livestock, forestry, and fish; (see also local food)
- medication. Wild plant species have been used for medicinal purposes since before the beginning of recorded history. For example, quinine comes from the cinchona tree (used to treat malaria), digitalis from the foxglove plant (chronic heart trouble), and morphine from the poppy plant (pain relief). According to the National Cancer Institute, over 70 % of the promising anti-cancer drugs come from plants in the tropical rainforests. Animals may also play a role, in particular in research. It is estimated that of the 250,000 known plant species, only 5,000 have been researched for possible medical applications.
- industry : for example, fibers for clothing, wood for shelter and warmth. Biodiversity may be a source of energy (such as biomass). Other industrial products are oils, lubricants, perfumes, fragrances, dyes, paper, waxes, rubber, latexes, resins, poisons, and cork, which can all be derived from various plant species. Supplies from animal origin include wool, silk, fur, leather, lubricants, and waxes. Animals may also be used as a mode of transport.
- tourism and recreation : biodiversity is a source of economical wealth for many areas, such as many parks and forests, where wild nature and animals are a source of beauty and joy for many people. Ecotourism, in particular, is a growing outdoor recreational activity. Ecologists and environmentalists were the first to insist on the economic aspect of biological diversity protection. Thus, E. O. Wilson wrote in 1992 that : The biodiversity is the one of the bigger wealths of the planet, and nevertheless the less recognized as such. Estimation of the value of biodiversity is a necessary precondition to any discussion on the distribution of biodiversity richnesses. This value can be divided into use value (direct such as tourism or indirect such as pollination) and non-use or intrinsic value. If biological resources represent an ecological interest for the community, their economic value is also increasing. New products are developed because of biotechnologies, and new markets created. For society, biodiversity also is a field of activity and profit. It requires a proper management setup to determine how these resources are to be used. The majority of species have yet to be evaluated for their current or future economic importance.

Ethical role of biodiversity

Finally, biodiversity has an ethical role if humans consider that other species have an intrinsic right to exist. Ecophilosophies such as deep ecology assert that a recognition of this intrinsic right makes it morally wrong to voluntarily cause extinction. The level of biodiversity is a good indicator of the state of our relationships with other living species. Biodiversity is also part of many cultures' spiritual heritage (see indigenous people and cultural diversity).

Scientific role of biodiversity

This is a fourth benefit separate from the three main ones. Biodiversity is important because each species can give scientists some clue as to how life evolved and will continue to evolve on Earth. In addition, biodiversity helps scientists understand how life functions and the role of each species in sustaining ecosystems. See also Environmental economics

Evaluation of biodiversity

Measurement of biodiversity

From the viewpoint previously defined, no single objective measure of biodiversity is possible, only measures relating to particular purposes or applications. For practical conservationists, this measure should quantify a value that is at the same time broadly shared among locally affected people. For others, a broader and economically more defensible definition is that measures should allow the ensuring of continued possibilities for both adaptation and future use by people, assuring environmental sustainability. As a consequence, biologists argued that this measure is likely to be associated with the variety of genes. Since it cannot always be said which genes are more likely to prove beneficial, the best choice for conservation is to assure the persistence of as many genes as possible. For ecologists, this approach is sometimes considered inadequate and too restricted.

Biodiversity: time and space

Biodiversity is not static: it is a system in constant evolution, from a species, as well as from an individual organism point of view. The average half-life of a species is estimated at between one and four million years, and 99% of the species that have ever lived on earth are today extinct. Biodiversity is not distributed evenly on earth. It is consistently richer in the tropics. As one approaches polar regions one finds larger and larger populations of fewer and fewer species. Flora and fauna vary depending on climate, altitude, soils and the presence of other species. For a listing of distinct ecoregions based on these distributions, see the WikiProject Ecoregions.

Species inventory

Systematics assesses biodiversity simply by distinguishing among species. At least 1.75 million species have been described; however, the estimates of the true number of current species range from 3.6 to more than 100 million. Some also say that the knowledge of the species and the families became insufficient and must be supplemented by a greater comprehension of the functions, interactions and communities. Moreover, exchanges of genes occurring between the species tend to add complexity to the inventory.

Hotspots of biodiversity

One definition of a biodiversity hotspot is a region with many endemic species. Hotspots tend to occur in areas of historically limited human impact and are generally very productive. As a result of the pressures of the growing human population, human activity in many of these areas is increasing dramatically. Most of these hotspots are located in the tropics. Some examples are the following:
- Brazil is said to represent 1/5 of the world biodiversity, with 50,000 plant species, 5,000 vertebrates, 10-15 million insects, millions of microorganisms, etc.
- India is said to represent 8% of the recorded species, with 47,000 plants species and 81,000 animals. See also: biogeography, Amazonian forest, extinction, unified neutral theory of biodiversity.

Threats to biodiversity

During the last century, erosion of biodiversity has been increasingly observed. Estimates of extinction rates are controversial, ranging from very low to upwards of 200 species a day, but all scientists acknowledge that the rate of species loss is greater now than at any time in human history, with extinctions occurring at rates hundreds of times higher than background extinction rates. Some studies show that about one of eight known plant species is threatened with extinction. Some estimates put the loss at thousands of species per year, though these are based on Species-area theory and are controversial. This figure indicates unsustainable ecological practices, because only a small number of species come into being each year. All agree that the losses are due to human activities, in particular destruction of plant and animal habitats. An increasing number of studies indicate that elevated rates of extinction are being driven by human consumption of organic resources. While most of the species that are becoming extinct are not food species, their biomass is converted into human food when their habitat is transformed into pasture, cropland, and orchards. It is estimated that more than 40% of the Earth's biomass is tied up in only the few species that represent humans, our livestock and crops. Because an ecosystem decreases in stability as its species are made extinct, these studies warn that the global ecosystem is destined for collapse if it is further reduced in complexity. Some justify this situation not so much by a species overuse or ecosystem degradation as by their conversion in very standardized ecosystems (e.g., monoculture following deforestation). Before 1992, others pointed out that no property rights or no access regulation of resources necessarily lead to their decrease (degrading costs having to be supported by the community). Dissenters (notably economist Bjørn Lomborg) argue that there is not enough data to support the view of mass extinction, and say abusive extrapolations are being made on the global destruction of rainforests, coral reefs, mangrove swamps, and other rich habitats. There is also a growing awareness that the movement and the introduction of exotic species around the world by humans is a potent threat to biodiversity. When exotic species are introduced to ecosystems by humans and establish self-sustaining populations, the endemic species in that ecosystem, that have not evolved to cope with the exotic species in question, cannot automatically be expected to survive. Indeed, in many situations some will not. The exotic organisms in questions may be predators and/or have features due to their evolutionary background and environment that makes them very competitive, and similarly makes endemic species very defenceless and/or uncompetitive against these exotic species. The rich diversity of unique species across many parts of the world that humans treasure exist only because they a separated by barriers - particularly seas and oceans - from other species of other land masses, particularly the highly fecund, ultra-competitive, generalist "super-species". These are barriers that could never be crossed by natural processes, except for many millions of years in the future through continental drift. However human beings have invented ships and aeroplanes. Now human beings have the power to bring into contact species that would never have encountered each other in their evolutionary history, and to do it with ease in weeks, days or even just hours. As a consequence of the above, it is likely that if human beings continue to unleash species of the world against each other by introductions - species that otherwise would never have encountered each other in their evolutionary history - many of the worlds ecosystems will end up dominated by a very few, cosmopolitan "super-species".

Biodiversity management: conservation, preservation and protection

The conservation of biological diversity has become a global concern. Although not everybody agrees on extent and significance of current extinction, most consider biodiversity essential. There are basically two main types of conservation options, in-situ conservation and ex-situ conservation. In-situ is usually seen as the ultimate conservation strategy. However, its implementation is sometimes unfeasible. For example, destruction of rare or endangered species' habitats sometimes requires ex-situ conservation efforts. Furthermore, ex-situ conservation can provide a backup solution to in-situ conservation projects. Some believe both types of conservation are required to ensure proper preservation. An example of an in-situ conservation effort is the setting-up of protection areas. An example of an ex-situ conservation effort, by contrast, would be planting germplasts in seedbanks. Such efforts allow the preservation of large populations of plants with minimal genetic erosion. The threat to biological diversity was among the hot topics discussed at the UN World Summit for Sustainable Development, in hope of seeing the foundation of a Global Conservation Trust to help maintain plant collections. See also: Conservation, Earth Day, Global 200, IUCN, Seedbank, World Ocean Day.

Juridical status of biological diversity

Biodiversity must be evaluated and its evolution analysed (through observations, inventories, conservation...) then it must be taken into account in political decisions. It is beginning to receive a juridical setting.
- "Law and ecosystems" relationship is very ancient and has consequences for biodiversity. It is related to property rights, private and public. It can define protection for threatened ecosystems, but also some rights and duties (for example, fishing rights, hunting rights).
- "Laws and species" is a more recent issue. It defines species that must be protected because threatened by extinction. Some people question application of these laws. The U.S. Endangered Species Act is an example of an attempt to address the "law and species" issue.
- "Laws and genes" is only about a century old. While the genetic approach is not new (domestication, plant traditional selection methods), progress made in the genetic field in the past 20 years lead to the obligation to tighten laws. With the new technologies of genetic and genetic engineering, people are going through gene patenting, processes patenting, and a totally new concept of genetic resource. A very hot debate today seeks to define whether the resource is the gene, the organism, the DNA or the processes. The 1972 UNESCO convention established that biological resources, such as plants, were the common heritage of mankind. These rules probably inspired the creation of great public banks of genetic resources, located outside the source-countries. New global agreements (e.g.Convention on Biological Diversity), now give sovereign national rights over biological resources (not property). The idea of static conservation of biodiversity is disappearing and being replaced by the idea of dynamic conservation, through the notion of resource and innovation. The new agreements commit countries to conserve biodiversity, develop resources for sustainability and share the benefits resulting from their use. Under these new rules, it is expected that bioprospecting or collection of natural products has to be allowed by the biodiversity-rich country, in exchange for a share of the benefits. Sovereignty principles can rely upon what is better known as Access and Benefit Sharing Agreements (ABAs). The Convention on Biodiversity spirit implies a prior informed consent between the source country and the collector, to establish which resource will be used and for what, and to settle on a fair agreement on benefit sharing. Bioprospecting can become a type of biopiracy when those principles are not respected. Uniform approval for use of biodiversity as a legal standard has not been achieved, however. At least one legal commentator has argued that biodiversity should not be used as a legal standard, arguing that the multiple layers of scientific uncertainty inherent in the concept of biodiversity will cause administrative waste and increase litigation without promoting preservation goals. See [http://www.law.nyu.edu/journals/envtllaw/issues/vol12/bosselman-for%20web.pdf Fred Bosselman, A Dozen Biodiversity Puzzles, 12 N.Y.U. Environmental Law Journal 364 (2004)]

Biodiversity and size bias

Biodiversity researcher Sean Nee, writing in the 24 June 2004 edition of Nature, points out that the vast majority of Earth's biodiversity is microbial, and that contemporary biodiversity science is "firmly fixated on the visible world" (Nee uses "visible" as a synonym for macroscopic). For example, microbial life is very much more metabolically and environmentally diverse than multicellular life (see extremophile).

Quotes from Sean Nee

- "the contribution of visible life to biodiversity is very small indeed".
- "On the tree of life, based on analyses of small-subunit ribosomal RNA, visible life consists of barely noticeable twigs. This should not be surprising — invisible life had at least three billion years to diversify and explore evolutionary space before the 'visibles' arrived".

Measures of biodiversity

There are three common metrics used to measure biodiversity.
- Species Richness
- Simpson Index
- Shannon-Wiener Index

External links

- [http://www.actionbioscience.org/index.html ActionBioscience], a project of the American Institute of Biological Sciences that examines biodiversity, environment, genomics and other issues in bioscience.
- [http://www.biodiv.org/convention/ Convention on Biological Diversity - Convention Text]
- [http://www.law-ref.org/CBD/index.html Convention on Biological Diversity at Law-Ref.org] - fully indexed and crosslinked with other documents
- [http://plato.stanford.edu/entries/biodiversity/ Stanford Encyclopedia of Philosophy: Biodiversity]
- [http://www.museums.org.za/bio/index.htm Biodiversity explorer]
- [http://biodiversityhotspots.org/ Website about hotsposts of biodiversity]
- [http://www.well.com/user/davidu/extinction.html Website about current rate of biodiversity loss and species extinction]
- [http://www.ericdigests.org/2000-2/biodiversity.htm Teaching about Biodiversity]
- [http://www.globio.info GLOBIO], an ongoing programme to map the past, current and future impacts of human activities on biodiversity
- [http://stort.unep-wcmc.org/imaps/gb2002/book/viewer.htm World Map of Biodiversity] an interactive map from the United Nations Environment Programme World Conservation Monitoring Centre

Directories

- [http://search.looksmart.com/p/browse/us1/us317914/us53774/us227678/ LookSmart - Biodiversity]
- [http://dmoz.org/Science/Environment/Biodiversity/ Open Directory Project - Biodiversity]
- [http://dir.yahoo.com/Science/Biology/Biodiversity/ Yahoo! - Biodiversity] Category:Ecology Category:Conservation Category:Scientific portmanteaus ja:生物多様性

Flora (plants)

In botany, flora (plural: floras or florae) has two meanings. The first refers to the plant life occurring in that area, especially the naturally occurring plant life. The second refers to a work which describes the species occurring in an area (either geographically or politically defined), with the aim of allowing identification. A flora often contains a diagnostic key. Traditionally floras are books, but some are now published on CD-ROM or websites. The term comes from Flora, the goddess of flowers in Roman mythology.

Classic floras

;Europe
- Paulli, Simon. Flora Danica. Denmark, 1647.
- Rupp, Heinrich Bernhard. Flora Jenensis Germany, 1718.
- Di Canio, Paolo. Flora Scorer. 1723.
- Linnaeus, Carolus. Flora Suecica. 1745. ;Indonesia Blume, Karl Ludwig, and Joanne Baptista Fischer. Flora Javae. 1828.

Modern floras

Americas

;Central & South America
- Flora Neoptropica (1968-ongoing) [http://www.nybg.org/bsci/ofn/ofn.html Organising committee website]. ;Caribbean
- Britton, N. L., and Percy Wilson. Scientific Survey of Porto Rico and the Virgin Islands — Volume V, Part 1: Botany of Porto Rico and the Virgin Islands: Pandanales to Thymeleales. New York: New York Academy of Sciences, 1924. ;North America
- [http://www.efloras.org/flora_page.aspx?flora_id=1 Flora of North America]
- Kearney, Thomas H. Arizona Flora. University of California Press, 1940.
- Hultén, Eric. Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants. Stanford University Press, 1968.
- Radford, Albert E. Manual of the Vascular Flora of the Carolinas. University of North Carolina Press, 1968.
- Hitchcock, C. Leo, and Arthur Cronquist. Flora of the Pacific Northwest. University of Washington Press, 1973.
- Chadde, Steve W., and Steve Chadde. A Great Lakes Wetland Flora. 2nd ed. Pocketflora Press, 2002. ISBN 0-9651-3855-0

Asia

;China
- [http://www.efloras.org/flora_page.aspx?flora_id=2 Flora of China]. ;Southeast Asia
- Flora Malesiana (1984-ongoing) [http://www.floramalesiana6.ph/about.html About Flora Malesiana].

Europe

;British Isles
- Anthony Stace, Clive, and Hilli Thompson (illustrator). A New Flora of the British Isles. 2nd ed. Cambridge University Press, 1997. ISBN 0-5215-8935-5.
- Beesley, S. and J. Wilde. Urban Flora of Belfast. Belfast: Institute of Irish Studies, Queen's University, Belfast, 1997.
- Killick, John, Roy Perry and Stan Woodell. Flora of Oxfordshire. Pisces Publications, 1998. ISBN 1-874357-07-2.
- Bowen, Humphry. The Flora of Dorset. Pisces Publications, 2000. ISBN 1-874357-16-1.

External links

- [http://www.efloras.org/index.aspx eFloras - a collection of on-line floras] Category:Botany Category:Ecology Category:Nonfiction books ms:Flora

Fauna (animals)

Fauna is a collective term for animal life. The corresponding term for plants is flora. Technically, the proper term for fauna plus flora is biota, but fauna is often used instead. In zoology and paleontology the term is often used to refer to the typical collection of animals (and sometimes plants) found in a specific time and/or place -- e.g. the 'Sonoran Desert fauna' or the 'Burgess shale fauna'. Paleontologists sometimes refer to a sequence of 80 or so faunal stages. Category:Zoology simple:Animalia

Ecosystems

In ecology, the word ecosystem is an abbreviation of the term, ecological system. Some consider this the basic unit in ecology. Ecosystems are not to be confused with biomes because they are smaller than biomes. They can be as big as the sahara desert, but as small as a pond. In general terms an ecological system can be thought of as an assemblage of organisms (plant, animal and other living organisms—also referred to as a biotic community or biocoenosis) living together with their environment (or biotope), functioning as a loose unit. That is, a dynamic and complex whole, interacting as an "ecological unit". Early conceptions of this unit were as a structured functional unit in equilibrium. This equilibrium was characterized by energy and matter flows between its constituent elements. Others considered this vision limited, and preferred to understand an ecosystem in terms of cybernetics. From this view an ecological system is not a structured functional unit in equilibrium, but a functional organisation at dynamic equilibrium, or what was also called steady state. This branch of ecology that gave rise to this view has become known as Systems Ecology. Steady state is understood as the phase of an ecological systems evolution when the organisms are "balanced" with each other and their environment. This balance is achieved through various types of symbiosis, such as predation, parasitism, mutualism, commensalism, competition, and amensalism. Introduction of new elements, whether abiotic or biotic, into an ecosystem tend to have a disruptive effect. In some cases, this can lead to ecological collapse and the death of many native species. The abstract notion of ecological health attempts to measure the robustness and recovery capacity for an ecosystem. That is, how far the ecosystem is away from steady state. The size and scale of an ecosystem can vary widely. It may be a whole forest, as well as a small pond, or even the geobiosphere itself. Different ecosystems are often separated by geographical barriers, like deserts, mountains or oceans, or are isolated otherwise, like lakes or rivers. As these borders are never rigid, ecosystems tend to blend into each other. As a result, the whole earth can be seen as a single ecosystem, or a lake can be divided into several ecosystems, depending on the scale used.

History

The term ecosystem first appeared in a 1935 publication by the British ecologist Arthur Tansley (Tansley, 1935). However, the term had been coined already in 1930 by Tansley's colleague Roy Clapham, who was asked if he could think of a suitable word to denote the physical and biological components of an environment considered in relation to each other as a unit. Tansley expanded on the term in his later work, adding the ecotope concept to define the spatial context of ecosystems (Tansley, 1939). Modern usage of the term derives from the work of Raymond Lindeman in his classic study of a Minnesota lake (Lindeman, 1942). Lindeman's central concepts were that of functional organisation and ecological energy efficiency ratios. This approach is connected to ecological energetics and might also be thought of as environmental rationalism. It was subsequently applied by H.T.Odum, sometimes called the 'father' of ecosystems ecology, in founding the transdiscipline known as Systems Ecology. Category:Ecology Category:Symbiosis

External link

- [http://www.ericdigests.org/2004-1/ecosystems.htm Teaching about Ecosystems]
- [http://www.millenniumassessment.org/en/index.aspx Millennium Ecosystem Assessment] (2005)
- [http://www.greenfacts.org/ecosystems/index.htm A popularized version of the Millennium Ecosystem Assessment] by GreenFacts.

References

- Lindeman, R. L. 1942. The trophic-dynamic aspect of ecology. Ecology 23: 399-418.
- Tansley, A. G. 1935. The use and abuse of vegetational concepts and terms. Ecology 16: 284-307.
- Tansley, A.G. 1939. The British Islands and their Vegetation. Volume 1 of 2. University Press, Cambridge, Cambridge, United Kingdom. 484 pg. Category:Ecology ko:생태계 ja:生態系

List of ecoregions

This is a list of ecoregions as compiled by the World Wildlife Fund (WWF). That group divides the Earth's land surface into 8 major ecozones containing 867 smaller ecoregions. Many consider this classification to be quite decisive, and some propose these as stable borders for bioregional democracy initiatives.

Terrestrial

Tropical and subtropical moist broadleaf forests

Afrotropical

- Guinean moist forests (Benin, Côte d’Ivoire, Ghana, Guinea, Liberia, Sierra Leone, Togo)
- Congolian coastal forests (Angola, Cameroon, Democratic Republic of Congo, Equatorial Guinea, Gabon, Nigeria, São Tomé & Príncipe, Republic of Congo)
- Cameroon highlands forests (Cameroon, Equatorial Guinea, Nigeria)
- Northeastern Congo basin moist forests (Central African Republic, Democratic Republic of Congo)
- Central Congo basin moist forests (Democratic Republic of Congo)
- Western Congo basin moist forests (Cameroon, Central African Republic, Democratic Republic of Congo, Gabon, Republic of Congo)
- Albertine rift montane forests (Burundi, Democratic Republic of Congo, Rwanda, Tanzania, Uganda)
- East African coastal forests (Kenya, Somalia, Tanzania)
- Eastern arc montane forests (Kenya, Tanzania)
- Madagascar forests and shrublands (Madagascar)
- Seychelles and Mascarenes moist forests (Mauritius, Reunion (France), Seychelles)

Australasia

- Sulawesi moist forests (Indonesia)
- Moluccas moist forests (Indonesia)
- Southern New Guinea lowland forests (Indonesia, Papua New Guinea)
- New Guinea montane forests (Indonesia, Papua New Guinea)
- Solomons-Vanuatu-Bismarck moist forests (Papua New Guinea, Solomon Islands, Vanuatu)
- Queensland tropical forests (Australia)
- New Caledonia moist forests (New Caledonia)
- Lord Howe-Norfolk Islands forests (Australia)

Indo-Malayan

- Southwestern Ghats moist forests (India)
- Sri Lankan moist forests (Sri Lanka)
- Northern Indochina subtropical moist forests (China, Laos, Myanmar, Thailand, Vietnam)
- Southeast China-Hainan moist forests (China, Vietnam)
- Taiwan montane forests (China)
- Annamite Range moist forests (Cambodia, Laos, Vietnam)
- Sumatran Islands lowland and montane forests (Indonesia)
- Philippines moist forests (Philippines)
- Palawan moist forests (Philippines)
- Kayah-Karen/Tenasserim moist forests (Malaysia, Myanmar, Thailand)
- Peninsular Malaysian lowland and mountain forests (Indonesia, Malaysia, Singapore, Thailand)
- Borneo Lowland and montane forests (Brunei, Indonesia, Malaysia)
- Nansei Shoto Archipelago forests (Japan)
- Eastern Deccan Plateau moist forests (India)
- Naga-Manupuri-Chin Hills moist forests (Bangladesh, India, Myanmar)
- Cardamom Mountains moist forests (Cambodia, Thailand)
- Western Java mountain forests (Indonesia)

Neotropical

- Greater Antillean moist forests (Cuba, Dominican Republic, Haiti, Jamaica, Puerto Rico)
- Talamancan and Isthmian Pacific forests (Costa Rica, Panama)
- Chocó-Darién moist forests (Colombia, Ecuador, Panama)
- Northern Andean montane forests (Colombia, Ecuador, Venezuela, Peru)
- Coastal Venezuela montane forests (Venezuela)
- Guianan moist forests (Brazil, French Guiana (France), Guyana, Suriname, Venezuela)
- Napo moist forests (Colombia, Ecuador, Peru)
- Río Negro-Juruá moist forests (Brazil, Colombia, Peru, Venezuela)
- Guayanan Highlands forests (Brazil, Colombia, Guayana, Suriname, Venezuela)
- Central Andean Yungas (Argentina, Bolivia, Peru)
- Southwestern Amazonian moist forests (Bolivia, Brazil, Peru)
- Atlantic forests (Argentina, Brazil, Paraguay)

Oceania

- South Pacific Islands forests (American Samoa, Cook Islands, Fiji, French Polynesia, Niue, Samoa, Tonga, Wallis and Futuna Islands)
- Hawai'i moist forests (Hawaii)

Tropical and subtropical dry broadleaf forests

Afrotropical

- Madagascar dry forests (Madagascar)

Australasia

- Nusu Tenggara dry forests (Indonesia)
- New Caledonia dry forests (New Caledonia)

Indo-Malayan

- Indochina dry forests (Cambodia, Laos, Thailand, Vietnam)
- Chhota-Nagpur dry forests (India)

Neotropical

- Mexican dry forest (Guatemala, Mexico)
- Tumbesian-Andean Valleys dry forests (Colombia, Ecuador, Peru)
- Chiquitano dry forest (Bolivia, Brazil)
- Atlantic dry forests (Brazil)

Oceania

- Hawaii dry forests (Hawaii)

Tropical and subtropical coniferous forests

Indomalaya

- Himalayan subtropical pine forests (Bhutan, India, Nepal, Pakistan)
- Luzon tropical pine forests (Philippines)
- Northeast India-Myanmar pine forests (India, Myanmar)
- Sumatran tropical pine forests (Indonesia)

Nearctic

- Bermuda subtropical conifer forests (Bermuda)
- Sierra Madre Occidental pine-oak forests (Mexico, United States)
- Sierra Madre Oriental pine-oak forests (Mexico, United States)

Neotropical

- Bahamian pine forests (Bahamas)
- Belizian pine forests (Belize)

- Central American pine-oak forests (El Salvador, Guatemala, Honduras, Mexico, Nicaragua)
- Cuban pine forests (Cuba)
- Hispaniolan pine forests (Dominican Republic, Haiti)
- Miskito pine forests (Honduras, Nicaragua)
- Sierra de la Laguna pine-oak forests (Mexico)
- Sierra Madre de Oaxaca pine-oak forests (Mexico)
- Sierra Madre del Sur pine-oak forests (Mexico)
- Trans-Mexican Volcanic Belt pine-oak forests (Mexico)

Temperate Broadleaf and Mixed Forests

Australasia

- Eastern Australia Temperate Forests (Australia)
- Tasmanian Temperate Rain Forests (Australia)
- New Zealand Temperate Forests (New Zealand)

Indo-Malayan

- Eastern Himalayan Broadleaf and Conifer Forests (Bhutan, China, India, Myanmar, Nepal)
- Western Himalayan Temperate Forests (Afghanistan, India, Nepal, Pakistan)

Nearctic

- Appalachian and Mixed Mesophytic Forests (United States)

Palearctic

- Southwest China Temperate Forests (China)
- Russian Far East Temperate Forests (Russia)

Temperate Coniferous Forests

Nearctic

Neotropical

- Valdivian temperate rain forests (Argentina, Chile)

Palearctic

- European-Mediterranean Montane Mixed Forests (Albania, Algeria, Andorra, Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, France, Germany, Greece, Italy, Liechtenstein, Macedonia, Morocco, Poland, Romania, Russia, Slovakia, Slovenia, Spain, Switzerland, Tunisia, Ukraine, Yugoslavia)
- Caucasus-Anatolian-Hyrcanian Temperate Forests (Armenia, Azerbaijan, Bulgaria, Georgia, Iran, Russia, Turkey, Turkmenistan)
- Altai-Sayan Montane Forests (China, Kazakstan, Mongolia, Russia)
- Hengduan Shan Coniferous Forests (China)

Boreal Forests/Taiga

Nearctic

- Muskwa/Slave Lake Boreal Forests (Canada)
- Canadian Boreal Forests (Canada)

Palearctic

- Ural Mountains Taiga (Russia)
- Eastern Siberian Taiga (Russia)
- Kamchatka Taiga and Grasslands (Russia)

Tropical and Subtropical Grasslands, Savannas and Shrublands

Afrotropical

- Horn of Africa Acacia Savannas (Eritrea, Ethiopia, Kenya, Somalia, Sudan)
- East African Acacia Savannas (Ethiopia, Kenya, Sudan, Tanzania, Uganda)
- Central and Eastern Miombo Woodlands (Angola, Botswana, Burundi, Democratic Republic of Congo, Malawi, Mozambique, Namibia, Tanzania, Zambia, Zimbabwe)
- Sudanian Savannas (Cameroon, Central African Republic, Chad, Nigeria, Democratic Republic of Congo, Eritrea, Ethiopia, Kenya, Nigeria, Sudan, Uganda)

Australasia

- Northern Australia and Trans-Fly Savannas (Australia, Indonesia, Papua New Guinea)

Indo-Malayan

- Terai-Duar Savannas and Grasslands (Bangladesh, Bhutan, India, Nepal)

Neotropical

- Llanos Savannas (Colombia, Venezuela)
- Cerrado Woodlands and Savannas (Bolivia, Brazil, Paraguay)

Temperate Grasslands, Savannas and Shrublands

Nearctic

- Northern Prairie (Canada, United States)

Neotropical

- Patagonian Steppe (Argentina, Chile)

Palearctic

- Daurian Steppe (China, Mongolia, Russia)

Flooded Grasslands and Savannas

Afrotropical

- Sudd-Sahelian Flooded Grasslands and Savannas (Cameroon, Chad, Ethiopia, Mali, Niger, Nigeria, Sudan, Uganda)
- Zambezian Flooded Savannas (Angola, Botswana, Democratic Republic of Congo, Malawi, Mozambique, Namibia, Tanzania, Zambia)

Indo-Malayan

- Rann of Kutch Flooded Grasslands (India, Pakistan)

Neotropical

- Everglades Flooded Grasslands (United States)
- Pantanal Flooded Savannas (Bolivia, Brazil, Paraguay)

Montane Grasslands and Shrublands

Afrotropical

- Ethiopian Highlands (Eritrea, Ethiopia, Sudan)
- Southern Rift Montane Woodlands (Malawi, Mozambique, Tanzania, Zambia)
- East African Moorlands (Democratic Republic of Congo, Kenya, Rwanda, Tanzania, Uganda)
- Drakensberg Montane Shrublands and Woodlands (Lesotho, South Africa, Swaziland)

Australasia

- Central Range Subalpine Grasslands (Indonesia, Papua New Guinea)

Indo-Malayan

- Kinabalu Montane Scrub (Malaysia)

Neotropical

- Northern Andean Paramo (Colombia, Ecuador, Peru, Venezuela)
- Central Andean Dry Puna (Argentina, Bolivia, Chile, Peru)

Palearctic

- Tibetan Plateau Steppe (Afghanistan, China, India, Pakistan, Tajikistan)
- Middle Asian Montane Steppe and Woodlands (Afghanistan, China, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan)
- Eastern Himalayan Alpine Meadows (Bhutan, China, India, Myanmar, Nepal)

Tundra

Nearctic

- Alaskan North Slope Coastal Tundra (Canada, United States)
- Canadian Low Arctic Tundra (Canada)

Palearctic

- Fenno-Scandia Alpine Tundra and Taiga (Finland, Norway, Russia, Sweden)
- Taimyr and Siberian Coastal Tundra (Russia)
- Chukote Coastal Tundra (Russia)

Mediterranean Forests, Woodlands and Scrub

Afrotropical

- Fynbos (South Africa)

Australasia

- Southwestern Australia Forests and Scrub (Australia)
- Southern Australia Mallee and Woodlands (Australia)

Nearctic

- California Chaparral and Woodlands (Mexico, United States)

Neotropical

- Chilean Matorral (Chile)

Palearctic

- Mediterranean Forests, Woodlands and Scrub (Albania, Algeria, Bosnia and Herzegovina, Bulgaria, Canary Islands, Croatia, Cyprus, Egypt, France, Gibraltar, Greece, Iraq, Israel, Italy, Jordan, Lebanon, Libya, Macedonia, Madeira Islands, Malta, Monaco, Morocco, Portugal, San Marino, Slovenia, Spain, Syria, Tunisia, Turkey, Western Sahara, Yugoslavia)

Deserts and Xeric Shrublands

Afrotropical

- Namib-Karoo-Kaokeveld Deserts (Angola, Namibia, South Africa)
- Madagascar Spiny Thicket (Madagascar)
- Socotra Island Desert (Yemen)
- Arabian Highland Woodlands and Shrublands (Oman, Saudi Arabia, United Arab Emirates, Yemen)

Australasia

- Carnavon Xeric Scrub (Australia)
- Great Sandy-Tanami Deserts (Australia)

Nearctic

- Sonoran-Baja Deserts (Mexico, United States)
- Chihuahuan-Tehuacán Deserts (Mexico, United States)

Neotropical

- Galápagos Islands Scrub (Ecuador)
- Atacama-Sechura Deserts (Chile, Peru)

Palearctic

- Central Asian Deserts (Kazakstan, Kyrgyzstan, Uzbekistan, Turkmenistan)

Mangroves

Afrotropical

- Gulf of Guinea Mangroves (Angola, Cameroon, Democratic Republic of Congo, Equatorial Guinea, Gabon, Ghana, Nigeria)
- East African Mangroves (Kenya, Mozambique, Somalia, Tanzania)
- Madagascar Mangroves (Madagascar)

Australasia

- New Guinea Mangroves (Indonesia, Papua New Guinea, Indo-Malayan)
- Sundarbans Mangroves (Bangladesh, India)
- Greater Sundas Mangroves (Brunei, Indonesia, Malaysia)

Neotropical

- Guianan-Amazon Mangroves (Brazil, French Guiana, Suriname, Trinidad and Tobago, Venezuela)
- Panama Bight Mangroves (Colombia, Ecuador, Panama, Peru)

Freshwater

Marine

External link

[http://www.panda.org/about_wwf/where_we_work/ecoregions/ecoregions.cfm List of ecoregions]

Continent

shows land mass with minimal distortion as only one continuous continent]] A continent (Latin continere, "to hold together") is a large continuous land mass. There are several conceptions of what a continent is, geographic, geologic, and tectonic.

Geographic continents

Because geography is defined by local convention, there are several conceptions as to which landmasses qualify as continents. There are names for six, but America is often divided, and Europe is often united with Asia. Ignoring cases where Antarctica is omitted, there are half a dozen lists. tectonic The 7-continent model is usually taught in Western Europe, the United States, Australia, and much of Asia. In Canada, the government-approved [http://atlas.gc.ca/site/english/maps/reference/international/world/referencemap_image_view Atlas of Canada] names 7 continents and teaches Oceania instead of Australia. The 6-continent combined-America model is taught in Iran, and Latin America. The 6-continent Eurasia model is preferred by the scientific community, and as such is commonly found in all parts of the world, but is especially used in Russia and other countries of Eastern Europe, and in Japan. Historians may use the 5-continent model in which North Africa is separated from Sub-Saharan Africa and attached to Eurasia (Jared Diamond) or the 4-continent Afro-Eurasian model (Andre Gunder Frank). In its original sense, "continent" meant (and still means) mainland. In the Greco-Roman world, there was but one known, the Continent, which we today call the Old World. In the mid 1600s Peter Heylin wrote in his Cosmographie that "A Continent is a great quantity of Land, not separated by any Sea from the rest of the World, as the whole Continent of Europe, Asia, Africa." As late as 1727 Ephraim Chambers wrote in his Cyclopædia, "The world is ordinarily divided into two grand continents: the old and the new." However, since Classical times this Continent was divided into "peninsulas" which also came to be called continents, since they were great land masses themselves. Through the Middle Ages, there were three such continents in the Western conception: Europe, Africa, and Asia. The European discovery of America in 1492 made four; and Australia in 1606 would make five, though not right away: as late as 1813 geographers wrote of Australia as "New Holland, an immense Island, which some geographers dignify with the appellation of another continent". However, dividing America in two was commonplace by this time, and would also produce a fifth continent. The idea of the Five Continents is still strong in Europe and Asia, and is represented by the five rings on the Olympic flag. Antarctica was sighted in 1820, for the sixth and last continent to be given a separate name, though a great "antarctic" (antipodean) landmass had been anticipated for millennia. Dividing the Americas now made seven continents, nicely symmetrical with the magical number of the Seven Seas, Seven Heavens, and the seven heavenly bodies that gave their names to the seven days of the week. However, this division never appealed to Latin America, which saw itself spanning America as a single landmass, and there the conception of six continents remains, as it does in scattered other countries such as Japan. From a modern perspective, the continent with the least reason for separate recognition is Europe, and in scientific circles people generally prefer to subsume Europe and Asia into Eurasia. This appealed to Russia, which spans Eurasia, and in Russia and (at least formerly) in Eastern Europe, Eurasia is or was taught as being one of six continents. Geographers and historians often find it useful to define larger land masses connected by land bridges: # Africa-Eurasia (also called Eurafrasia): the combined land mass of Africa and Eurasia; # America (or the Americas): the combined land mass of North America and South America; # Laurasia: the combined land mass of Eurasia and North America, which were connected by Beringia during the Ice Age; # Sahul: the combined land mass of Australia, New Guinea, and Tasmania during the Ice Age. That is, during the last Ice Age, there were three large landmasses: Africa-Eurasia + America (which has no name), Sahul, and Antarctica. These larger land masses are usually considered supercontinents rather than continents, however. In the last century it has also become conventional to subdivide Eurasia into the regions of Europe, Asia, and the Middle East. America is often divided into the regions of North America, Central America, and South America. Continents are also sometimes subdivided into subcontinents that are isolated by geological features. The prototype of this is the Indian subcontinent. Islands are usually considered to belong geographically to the continent they are closest to. The Coral Sea and South Pacific islands may be associated with Australia/Australasia to form the "continent" of Oceania (though the Pacific islands without Australia are also called Oceania). The British Isles have always been considered part of Europe, and Greenland is considered part of North America. When the Continent is referred to without clarification by a speaker of British English, it is usually presumed to mean Continental Europe, that is Europe, explicitly excluding Great Britain and Ireland. The Continental United States excludes Hawaii. Contiguous or Co(n)terminous United States means the United States without Alaska or Hawaii (the "Lower 48"), but it is very common for people to say continental for contiguous. See also List of countries by continent, Satellite Images of Continents.

Geologic continents

Geologically, the surface of Earth consists of many tectonic plates, consisting of rigid lithospheric mantle and crust moving together over the much less viscous asthenosphere. Continental crust is primarily granitic in composition, overlain by sedimentary and metamorphic rocks. Much of the continental crust extends above sea level as dry land. Oceanic crust is basaltic in composition, and much thinner than continental crust, thus generally lying below sea level. Although from a human perspective shallow inland seas such as the Bering Sea appear to divide up land masses into continents, such ephemeral features do not define continents geologically. For instance, many times over the past few million years, the continents of Eurasia and America were connected by dry land. A geologic continent, therefore, is a continuous piece of continental crust, whether wet or dry at a particular time. As such, Laurasia and Africa-Arabia are one continent, which for the past three million years has also been linked to South America. This world-spanning land mass has no name except for the Classical meaning of "The Continent". The other large geologic continents are Sahul and Antarctica, but there are many so-called microcontinents as well: Madagascar, the Seychelles (the northern Mascarene Plateau), New Zealand, New Caledonia, etc., which are splinters of the ancient supercontinent of Gondwana. Note that volcanic Iceland is an exposed bit of oceanic crust at the mid-ocean ridge, and therefore not a microcontinent. Likewise, the British Isles, Sri Lanka, Borneo, and Newfoundland are integral parts of the Laurasian continent which happen to be separated by shallow (and temporary) inland seas flooding its margins.

Tectonic plates

During the 20th century, it became accepted by geologists that continents move location on the face of the planet over the geologic timescale, a process known as continental drift, explained by the theory of plate tectonics. It is the tectonic plates that have drifted, broken apart and joined together over time to give rise to the continents we now recognize. Consequently, in the geological past and prior to the present continents, other continents existed - see :Category:Historical continents. Occasionally there are calls for the continents to be defined by the tectonic plates that carry them. However, not only would this make Arabia on the Arabian plate and India on the Indian plate continents, but also Central America on the Caribbean plate and California on the Pacific plate, and this definition has never been widely accepted.

Ecoregion

See also

Sources

External links

World Wildlife Fund

Presidents

International directors

External links

Landform

See also

List of landforms

Slope landforms

Coastal and oceanic landforms

Fluvial landforms

Mountain and glacial landforms

Volcanic landforms

Erosion landforms

External links

Climate

Climate vs weather

Climate determinants

Climate indices

Classifications

See also

Historical climates

National climates

External links

Notes

Biodiversity

Etymology

Biodiversity definitions

Origin of life and biodiversity evolution

Benefits of biodiversity

Ecological role of biodiversity

Economic role of biodiversity

Ethical role of biodiversity

Scientific role of biodiversity

Evaluation of biodiversity

Measurement of biodiversity

Biodiversity: time and space

Species inventory

Hotspots of biodiversity

Threats to biodiversity

Biodiversity management: conservation, preservation and protection

Juridical status of biological diversity

Biodiversity and size bias

Quotes from Sean Nee

Measures of biodiversity

See also

External links

Directories

Flora (plants)

Classic floras

Modern floras

Americas

Asia

Europe

See also

External links

Fauna (animals)

Ecosystems

History

See also

External link

References

List of ecoregions

Terrestrial

Tropical and subtropical moist broadleaf forests

Afrotropical

Australasia

Indo-Malayan

Neotropical

Oceania

Tropical and subtropical dry broadleaf forests

Afrotropical

Australasia

Indo-Malayan

Neotropical

Oceania

Tropical and subtropical coniferous forests